Payroll systems like ADP and Paychex are a necessary business evil; they're difficult to navigate and expensive. Three founders in Silicon Valley have designed a more attractive, cloud-based solution called ZenPayroll and in just eight months, they've seen a lot of traction.

The startup is now processing over $100 million for the businesses that use it.* Its CEO, Joshua Reeves, won't reveal how many companies are using ZenPayroll, but he says "thousands of employees are getting paid through it" and that his biggest customer represents less than 2% of that $100 million milestone.